Bulb non working how do you get to the bulb - Neff B7740N0GB Microwave Oven

It is common for the light circuit trace to blow out if the light bulbs shorted out when removed while energized. If the trace is good then there could be a bad light relay

Not sure as microwave manuals often will not discuss this due to consumer safety concerns, but here is some info from a good source on Microwave repair:

"You would think that something like replacing a light bulb would be trivial and self evident. Unfortunately, not always so with microwave ovens. Light bulbs may be typically located in any of 3 places:

1. Oven chamber - it may be behind a mesh grill requiring a screw or snap to be removed. This is the easiest.
   
2. Rear - the bulb may be in a recessed compartment accessible by removing a screw or two on the back of the oven.
   
3. Inside - it may be behind a non-removable grille requiring the removal of the cover.

These are typically not your usual vanilla flavored appliance bulbs either.

Bad connections are also possible but not that likely."

Remember, while you can do some repairs on your microwave, what you don't know can kill you... even on an unplugged microwave, so make sure you understand the dangers and how to reduce them before you try anything inside a microwave. If you want to do more yourself, follow the above link and take note of the safety instructions.

In cheaper ovens it is not possible to get to without removing the outer case, so is not recommended by the manufacturer - They want you to buy a new oven because the lamp fails.

On the other hand, if you are meticulous, you can unplug, remove the outer casing and access the bulb, BUT YOU MUST ENSURE ALL SCREWS ARE RETURNED TO ORIGINAL LOCATIONS after repair.

Bulb is likely to be non-standard, but easy to fit.

It is very important that all shielding is replaced exactly as fitted, and the outer case is undamaged and refitted perfectly - or microwave energy is likely to leak at these points.

Lowes will post out the correct bulb for your unit if you supply the model. Putting in a non standard bulb is nit recomended.

If there are 2 bulbs try swapping them around. If the night light works then you just need a bulb. Take the bad one with you and match it up at a parts store. Some actually have a dimmer circuit programmed in the board and that will not be a easy fix. Do you hear a click when you try to activate the night mode? If you cannot find a bulb or do not want to replace or repair the unit just disclose the non working light. I was in real estate for a couple years and a burned out bulb will not be a deal breaker as long as they are told up front.
Eric

We see (and repair) this a lot. The problem is on the control panel, which we regularly repair nationwide by mail for $39.95 postpaid in about a week.

At our Web site, you can get details of our service, plus we have a video available showing how to remove a typical over the range control panel assembly in under 5 minutes.

This light failure often occurs when a bulb goes out and the filament shorts, or when the bulbs are removed or installed without first unplugging the oven from the power line. Either can cause such a failure on the controller.

This can often also affect the exhaust fan operation, too. The lights and fan can be inoperable or stuck on too.

Feel free to contact me directly (and please remind me of your full model number) for more information & help.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

William E. Miller
[email protected]
http://www.microwavedisplay.com

Remove the light bulb, if it still blows the fuse then it's not a bulb problem. More than likely the Magnetron has gone bad and is shorting. Be extremely carefull working inside any Microwave, it can be very dangerous! Sorry to say, but it sounds like it would be an expensive repair compared to a new (or used) oven.

if there is a small cover on the side of the unit then the bulb will be under there if non you will have to remove the entire cover from the unit if you are not qaulified to do this then you need to take it to a repairer
cheers grant

The bulb should be squeaky clean prior to installation. If any oils from the skin get on the bulb (or grease from cooking) that will shorten its life considerably. Always use the hood fan when cooking on the stovetop to prevent buildup of grease or moisture inside the microwave controls or cooktop lights. It might be that the door is being slammed while the bulbs are on - that can shorten their life, too. You might visit a home center (Home Depot or Lowe's, etc.) and see if they have any higher quality non-Chinese bulbs. Always be sure to disconnect power from the microwave completely before removing or installing the bulbs. Failure to do so can damage the control board. We repair a lot o control boards because of this type or failure.

Are any other bulbs in the home going out prematurely? If so, I would check the actual voltage of your power outlets. If not, the bulbs may be getting grease or debris on them from stovetop cooking. This can cause hot psots and premature failure. I recommend wiping them clean with alcohol on a cloth before installing them. I recommend that folks always have their hood fan on when cooking on the stovetop. Also, you might check with a local home center (Lowe's, Home Depot, etc.) to see if they have some high-quality (non-Chinese) substitutes.